Absorbent article

ABSTRACT

An absorbent article, such as a sanitary napkin, is disclosed which is designed to absorb menstrual fluid. The absorbent article includes a liquid-impermeable baffle, a first absorbent layer and a second absorbent layer. The second absorbent layer is positioned between the baffle and the first absorbent layer and has a higher transverse wicking rate than the first absorbent layer. The absorbent article can be visually inspected to determine if it is linear its maximum fluid capacity before leakage occurs.

This is a continuation application of application Ser. No. 08/048,640,filed on Apr. 16, 1993, now abandoned, which is a continuationapplication of application Ser. No. 07/811,388, filed Dec. 20, 1991,which has issued to U.S. Pat. No. 5,219,341.

FIELD OF THE INVENTION

This invention relates to an absorbent article for absorption ofmenstrual fluid. It is particularly directed to sanitary napkins.

BACKGROUND OF THE INVENTION

Absorbent articles, classified as sanitary napkins, catamenial pads orfeminine pads, are designed to be worn by a female to absorb menstrualfluids and other excrements discharged by the body during a menstrualperiod. Sanitary napkins are external devices which are generally heldin position by an adhesive or by a mechanical attachment to anundergarment. Such products differ from tampons which are classified asinternal devices and which are designed to be physically inserted intothe vagina. Functionally, sanitary napkins are different from otherexternal devices, such as pantiliners or panty shields, in that they aregenerally constructed to absorb a greater quantity of body fluid and aredesigned to be worn for a longer period of time; for example, overnightif needed.

In order to adequately perform their function, modern sanitary napkinsare constructed of highly absorbent materials. However, if any absorbentmaterial is utilized to, or near, the point where it becomes fullysaturated, there is a possibility that leakage of body fluid could occurwhich might stain the user's clothing.

It is, therefore, desirable to construct an absorbent article whichcould be visually examined to determine if it is near itsfluid-saturation point. Quite often, the absorption of body fluids isinto a target zone on the top of the product; and it is not clear, fromlooking at the top of the product, if the product is close to beingsaturated. It is also difficult to tell when the target area is so closeto being fully saturated that leakage may soon occur.

Therefore, there is a need to provide an absorbent article which canprovide the user with a quick visual inspection to determine if it isnear its absorption limits. If the product is close to its limit, theuser could then replace it before leakage occurs.

There are several United States patents which teach the advantages ofusing an absorbent material which has good fluid-wicking properties forat least a portion of the absorbent layer. U.S. Pat. No. 4,732,312issued to Fender et al. teaches an absorbent pad containing a nonwovenhydrophilic thermoplastic filamentary microfiberous web as part of theabsorbent material. The microfiberous web exhibits good wicking andfluid-retention properties. The microfiberous web is not used to providean indication that the pad is close to absorbent capacity.

A second patent, U.S. Pat. No. 3,525,338 issued to Bernardin, disclosesutilizing a layer of glass microfibers as part of the absorbentmaterial. The glass microfiberous layer has good absorbent capacity andwicking capabilities. When a layer of glass microfibers is depositedhorizontally between two layers of conventional absorbent material, theabsorbent capacity of the sanitary napkin is increased as well as itsefficiency. The latter is due to the lateral wicking properties of thelayer of glass microfibers. The use of absorbent materials, havingvarying transverse wicking rates which can serve as a visual indicator,is not taught in this patent. Furthermore, neither Fender nor Bernardinteach using layers with various wicking rates as a method of providingan indication of the saturation level of an absorbent article.

There is also a need to design an absorbent article, where the crotchportion of the user's undergarment, to which the absorbent article isattached, will not fold onto the body-facing side of the product. Thiswill assist in preventing the undergarment from becoming stained by bodyfluid. One method of overcoming this problem is to design absorbentarticles with flaps or wings which extend outward from the centralabsorbent. However, the addition of flaps or wings makes the productmore expensive. Typically, sanitary napkins having flaps or wings use acentral adhesive strip which attaches the product to the crotch portionof a user's undergarment. The side flaps or wings are then folded aroundthe outer surface of the undergarment to protect the undergarment frombecoming stained. Some U.S. patents which teach the use of flaps orwings include the following.

U.S. Pat. No. 2,787,271 issued to Clark describes a sanitary napkincomprising a rectangular central pad having a pair of lateral flapsintegrally formed with the pad. The flaps are adapted to fold downwardand bear against the inner surface of the wearer's thighs. The flaps orwings are designed to stop any overflow of body fluid from staining theuser's clothing. The central pad has an absorbent core body whichextends without interruption into the lateral flaps.

U.S. Pat. No. 3,397,697 issued to Rickard describes a disposablesanitary shield for undergarments. This shield comprises an elongatedsheet of flexible material divided into at least two panels which arejoined by an intermediate neck-like portion. Portions of the panels,located adjacent to the neck-like portion, include wing-like flaps whichare adapted to be folded over each other. This enables the flaps toencircle the crotch portion of the undergarment and prevent staining.

U.S. Pat. No. 4,285,343 issued to McNair describes a sanitary napkinhaving a central absorbent pad with laterally extending side panels. Theside panels can be formed either integrally with the central absorbentor be formed separately and then secured to the longitudinal edges ofthe central absorbent.

U.S. Pat. No. 4,687,478 issued to Van Tilburg describes a sanitarynapkin having two flaps that extend outward from an absorbent means. Theabsorbent means is secured in the crotch of a panty, and the flaps aresecured about the elastic edges of a panty by an adhesive.

Despite the teachings of the prior art, there is still a need for anabsorbent article which can be visually inspected to determine if it isat, or near, its fluid-saturation limit.

SUMMARY OF THE INVENTION

Briefly, this invention relates to absorbent articles, such as sanitarynapkins, which are designed to absorb menstrual fluid and otherexcrements discharged by the body during a menstrual period. Theabsorbent article provides a user with the ability to quickly determineif it is approaching its saturation limit. The absorbent articleincludes a liquid-impermeable baffle and first and second absorbentlayers. The second absorbent layer is positioned between the baffle andthe first absorbent layer and has a higher transverse wicking rate thanthe first absorbent layer. Consequently, body fluid that works throughthe thickness of the first absorbent layer spreads in a transversedirection on the second absorbent layer at a faster rate than it does onthe first absorbent layer. This feature allows the fluid to reach theouter or lateral edges of the second absorbent layer faster than fluidthat remains in the first absorbent layer. The presence of extensivestaining, near the side edges of the second absorbent layer, serves as asignal that the product is near its maximum fluid capacity. The secondabsorbent layer is wider along its central transverse axis than is thefirst absorbent layer. This assures that the lateral edges of the secondabsorbent layer are visible to the user when she looks down onto the topof the absorbent article.

The absorbent article can optionally include a third absorbent layerwhich is positioned between the first and second absorbent layers. Thesecond absorbent layer will be wider, along its central transverse axis,than either the first or the third absorbent layers. When a thirdabsorbent layer is utilized, it will not have as high a transversewicking rate as the second absorbent layer. This will hold true evenwhen the third absorbent layer functions as the primary absorption layerof the absorbent article.

The general object of this invention is to provide an absorbent articlehaving two absorbent layers, wherein the lower layer has a greatertransverse wicking rate than the first layer. A more specific object ofthis invention is to provide a sanitary napkin which enables the user tovisually inspect the product to see if it is approaching its maximumfluid capacity.

Another object of this invention is to provide an absorbent articlewhich is easy to manufacture and is relatively low in cost.

Still another object of this invention is to provide an absorbentarticle, which utilizes at least two separate and distinct absorbentlayers, wherein the upper absorbent layer is narrower in size than alower layer.

Still further, an object of this invention is to provide an absorbentarticle which has improved fluid absorbency features.

Other objects and advantages of the present invention will become moreapparent to those skilled in the art in view of the followingdescription and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective top view of an absorbent article having aportion cut away to show the inner construction thereof.

FIG. 2 is a perspective top view of another embodiment of an absorbentarticle having a portion cut away to show the inner constructionthereof.

FIG. 3 is a cross-sectional view of another embodiment of an absorbentarticle taken across its transverse axis.

FIG. 4 is a perspective top view of another embodiment of an absorbentarticle having a portion cut away to show the inner constructionthereof.

FIG. 5 is a perspective top view of another embodiment of an absorbentarticle having a portion cut away to show the inner constructionthereof.

FIG. 6 is a partially cut away perspective view of another embodiment ofan absorbent article showing the use of an intermediate baffle layerpositioned between first and second absorbent layers.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, an absorbent article 10 in the form of a sanitarynapkin is shown which can be worn by a female to absorb body fluids suchas menses, blood, urine, and other excrements discharged during amenstrual period. The absorbent article 10 is about 150 millimeters (mm)to 300 mm long, about 50 mm to 125 mm wide and has a generally ovalshape. Other shapes, including hourglass, dogbone and racetrack, arecontemplated. The absorbent article 10 should have a caliper orthickness of less than about 15 mm, preferably less than about 10 mm,and most preferably, less than about 5 mm.

The absorbent article 10 includes a bodyside cover 11, which is liquidpermeable, a first absorbent layer 12, a second absorbent layer 13 and aliquid-impermeable baffle 14. The first absorbent layer 12 can behourglass in shape and should not be as long or as wide as the cover 11.The bodyside cover 11 has an upper surface 16 which contacts the body ofthe user. The first absorbent layer 12 can be secured to, or retainedon, the second absorbent layer 13. The second absorbent layer 13 iswider, along its central portion, than the first absorbent layer 12. Thesecond absorbent layer 13 can, in turn, be secured to, or retained on, atop surface 17 of the baffle 14. The baffle 14 should generally have thesame dimensions as the bodyside cover 11. The bottom side of the baffle14 will contact the inner surface of the undergarment worn by the userof the absorbent article 10.

The liquid-permeable cover 11 is designed to contact the body of thewearer and can be constructed of a woven or nonwoven, natural orsynthetic, material which is easily penetrated by body fluid. Suitablematerials include bonded carded webs of polyester, polypropylene,polyethylene, nylon, or other heat-bondable fibers. Other polyolefins,such as copolymers of polypropylene and polyethylene, linear low-densitypolyethylene, finely-perforated film webs and net material, also workwell. Particularly preferred are composite materials of a polymer and anonwoven fabric material. The composite sheets are generally formed byextrusion of the polymer onto a web of spunbond material to form anintegral sheet. This material is preferred, because the outer fabricsurface is not irritating to the skin of the wearer and has a cushionedfeel.

The walls of the absorbent article 10 generally extend up, into thecrease between the legs and the pudendum of the wearer, and have acushioned feel. Therefore, the outer wall portions may come in contactwith the legs of the wearer and should provide a comfortablenonirritating feel.

Another preferred material for the cover 11 is a spunbond web ofpolypropylene. The web can contain about 1 to 6% titanium dioxidepigment to give it a clean, white appearance. A uniform spunbondmaterial is desirable, because it has sufficient strength, after beingperforated in the longitudinal direction, to resist being torn or pulledapart during use. The most preferred polypropylene webs have a weight ofbetween about 18 and 40 grams per square meter. An optimum weight isbetween about 30 and about 40 grams per square meter.

Liquid-permeable covers utilized on absorbent articles, especiallysanitary napkins, can be comprised of a white material. White materialhas good fluid-masking properties and can hide the stain of liquid thathas passed through it. However, the advantages of the present inventionare best realized if the liquid-permeable cover 11 is sufficientlytransparent to enable a user to examine the absorbent article 10 fromits top side. This examination will determine if any fluid has spread ina transverse direction, that is, in a direction perpendicular to thelongitudinal central axis X--X of the product. The transverse centralaxis Y--Y of the absorbent article 10 is perpendicular to thelongitudinal edges 18 and 19 of the second absorbent layer 13.

The liquid-permeable cover 11 can also contain a plurality of apertures(not shown) formed therein. Such apertures can be arranged along thelongitudinal center axis X--X, if desired, and are intended to increasethe rate at which body fluids can penetrate down into the firstabsorbent layer 12.

With apertures present, body fluid, which is deposited at or near theapertures, rapidly migrates into the first absorbent layer 12. Thishelps maintain a perceivably drier surface than when the apertures arenot employed. Therefore, while the apertures are not essential, somefunctional advantages are obtained.

The liquid-permeable cover 11 can also be treated with a surfactant tomake it more hydrophilic and, thereby, aid in the absorption of theliquid. The surfactant can include topical additions or internallyapplied materials like polysiloxanes.

The baffle 14 permits the passage of air or vapor out of the absorbentarticle 10 while blocking the passage of body fluids and liquids fromthe absorbent layer 12 and 13. The baffle 14 can be made from anydesired material that has these properties. A good material is amicro-embossed, polymeric film, such as polyethylene or polypropylene.Bicomponent films can also be used. A preferred material is polyethylenefilm. Most preferably, the baffle 14 will be comprised of a polyethylenefilm having a thickness in the range of from about 0.5 to about 2.0 mm.

As indicated, the liquid-impermeable baffle 14 is coextensive with theliquid-permeable cover 11 and is adhered to the cover 11 in those areaswhere the cover 11 and the baffle 14 are in face to face contact. Themethod of adhering the cover 11 to the baffle 14 may be any suitablemethod that does not leave a hard, uncomfortable residue that would beannoying to the wearer. Typical of sealing methods are heat sealing andadhesive sealing. Another method is ultrasonically bonding on a lineinward from the edge of the absorbent article 10. When this is done, aloose flap or fringe of material usually extends about a quarter inchoutward from the bond line about the periphery of the product. Thisresults in a neat bond line with less tendency for the material to beperforated than by heat sealing.

A particular advantage of the absorbent article 10 is that it providesan indicator when it is near to its maximum fluid-saturation point. Theindicator begins to function when fluid begins to migrate down into thesecond absorbent layer 13. As indicated, the second absorbent layer 13is comprised of a material that has a higher transverse wicking ratethan that of the first absorbent layer 12. Body fluid, which reaches thesecond absorbent layer 13, will migrate in a transverse direction to theouter edges 18 and 19 faster than fluid in the first absorbent layer 12can reach the longitudinal edges 20 and 21. Therefore, a user canvisibly inspect the absorbent article 10 from its top surface todetermine if it needs to be replaced. If fluid is detected near thelateral edges 18 and 19 of the second absorbent layer 13, the user willhave a clear indication that the absorbent article 10 needs replacing.To facilitate such an inspection, the second absorbent layer 13 shouldbe wider, along its central transverse axis, than the first absorbentlayer 12. It should be noted that the central transverse axis of each ofthe layers, 12 and 13 respectively, will generally line up with thecentral transverse axis of the absorbent article 10. Preferably, thesecond absorbent layer 13 should be as visually distinctive as possiblefrom the other layers of the absorbent article 10. One way of achievingthis would be to make the second absorbent layer 13 a different colorfrom the other layers. However, care should be taken to utilize a colorfor the second absorbent layer 13 that would highlight, rather thanmask, the presence of fluid thereon.

The cover 11 and the baffle 14 will, in combination, enclose the firstabsorbent layer 12 and the second absorbent layer 13. The secondabsorbent layer 13 will be located between the first absorbent layer 12and the baffle 14. Both layers, 12 and 13 respectively, are comprised ofabsorbent material. Typically, the first absorbent layer 12 will becomprised of a material that is more absorbent than the materialcomprising the second absorbent layer 13. As indicated above, the secondabsorbent layer 13 is comprised of a material that has a highertransverse wicking rate than the material which comprises the firstabsorbent layer 12. The first absorbent layer 12 will, as the primaryabsorbent layer, typically be thicker than the second absorbent layer13. It should be emphasized that the values relating to absorbency andthe transverse wicking rate are relative for any particular style ofabsorbent article. It is, therefore, quite possible that one particularstyle of absorbent article may utilize the same material in its secondabsorbent layer as that utilized as the first absorbent layer in anotherabsorbent article.

The absorbent materials used in the absorbent article 10 are designed toabsorb body exudates, including menstrual fluids, catamenial fluids,blood and urine. Suitable materials include wood pulp fluff, rayon,cotton and meltblown polymer, such as polyester, polypropylene orcoform. Coform is a meltblown air-formed combination of meltblownpolymers, such as polypropylene, and absorbent staple fibers, such ascellulose. A preferred material is wood fluff, for it is low in cost,relatively easy to form and has good absorbency.

The absorbent material may be a composite comprised of a hydrophilicmaterial that can be formed from various natural or synthetic fibers,wood pulp fibers, regenerated cellulose or cotton fibers, or a blend ofpulp and other fibers. A preferred material is an airlaid tissue. Theabsorbent layers may also be comprised of other well-known materialsused in absorbent articles, including multiple layers of cellulosewadding, rayon fibers, cellulose sponge, hydrophilic synthetic sponge,such as polyurethane, and the like.

The absorbent layers 12 and 13 may contain superabsorbent particleswhich are extremely effective in retaining body fluids. Superabsorbentshave the ability to absorb a large amount of fluid in relation to theirown weight. Typical superabsorbents used in absorbent articles, such assanitary napkins, can absorb anywhere from 5 to 60 times their weight inbody fluids. However, the absorption mechanism of the superabsorbents isusually slower than the rate of fluid absorption by cellulose fluffmaterial. The placement of the superabsorbent particles in the centralportion of the absorbent article 10 provides additional time for thesuperabsorbent particles to absorb the body fluid temporarily retainedby a transfer member.

It has been found that superabsorbents having a high mechanicalstability in the swollen state, an ability to rapidly absorb fluid, andthose having a strong liquid-binding capacity perform well in catamenialdevices. Hydroxyfunctional polymers have been found to be goodsuperabsorbents for this application. The superabsorbent can be ahydrogel-forming polymer composition which is water-insoluble, slightlycross-linked, and partially neutralized. It can be prepared fromunsaturated polymerizable, acid group-containing monomers andcross-linked agents. A hydrogel-forming polymer, which is a partiallyneutralized cross-linked copolymer of polyacrylic acid and polyvinylalcohol, is preferred. After a polymer is formed, it is mixed with abouta 1% anhydrous citric acid powder. The citric acid has been found toincrease the ability of the superabsorbent to absorb menses and blood.This is particularly good for use in a sanitary napkin or feminine pad.The finely ground, anhydrous citric acid powder, which is void of water,along with trace amounts of fumed silica, is mixed with the polymerwhich has been screened to an appropriate particle size. This mixturecan then be formed into a composite or a laminate structure. Suchsuperabsorbents can be obtained from Dow Chemical, Hoechst-Celanese, andStockhausen, Inc., among others, and are a partially neutralized salt ofcross-linked copolymer of polyacrylic acid and polyvinyl alcohol havingan absorbency under load value above 25.

One combination of the absorbent layers 12 and 13 is for the firstabsorbent layer 12 to be made up of cellulose fluff fibers and thesecond absorbent layer 13 to be made up of meltblown polypropylene. Inanother embodiment, the first absorbent layer 12 can be a compositecomprised of meltblown fibers and a superabsorbent. The first absorbentlayer 12 can also be a laminate comprised of a hydrocolloid materialenclosed in a hydrophilic tissue, such as airlaid tissue. In anotherembodiment, at least one of the absorbent layers 12 or 13 may contain,along its periphery, a fluid-tight seal which can be constructed out ofa material which is the same as the baffle 14.

Referring again to FIG. 1, the second absorbent layer 13 is depictedhaving a length, as measured along longitudinal axis X--X, which is lessthan the length of the first absorbent layer 12. However, it isunderstood that this feature is an optional embodiment, and the lengthof the second absorbent layer 13 can be equal to, or greater than, thelength of first absorbent layer 12. The second absorbent layer 13 shouldpreferably be wider, along its central transverse axis Y--Y, than thefirst absorbent layer 12. This will enable a wearer to determine, fromviewing the top surface 16 of the absorbent article 10, whether fluidhas spread outward to the longitudinal side edges 18 and 19 of thesecond absorbent layer 13. If liquid has migrated outward to the edges18 and 19, the user will know that it is time to replace the product.

The first absorbent layer 12 can have an hourglass or dogbone shape witha narrow portion in the middle. In such an embodiment, the secondabsorbent layer 13 can have an oval shape. Preferably, the firstabsorbent layer 12 will be thicker at the narrow, middle portion toprovide added absorbency in this critical area. Most preferably, thefirst absorbent layer 12 will be thicker throughout than the secondabsorbent layer 13. Alternatively, the absorbent article 10 can have auniform thickness with a higher absorbency material located in thecenter portion than at the ends. Higher absorbency may be achieved byusing fibers of greater absorbency or by adding superabsorbents to thefirst absorbent layer 12.

Referring to FIG. 2, an absorbent article 10' is depicted having a cover11, a baffle 14, and first, second and third absorbent layers 12, 13 and15, respectively. The third absorbent layer 15 is positioned between thefirst absorbent layer 12 and the second absorbent layer 13. The secondabsorbent layer 13 should have a higher transverse wicking rate than thethird absorbent layer 15. The second absorbent layer 13 will preferablybe wider, along its transverse central axis Y--Y, than the thirdabsorbent layer 15. When the third absorbent layer 15 is positionedintermediate the absorbent layers 12 and 13, the third absorbent layer15 will typically be the primary absorbent layer. As the primaryabsorbent layer, it will be thicker and have a higher absorbency ratethan the first absorbent layer 12.

Referring to FIG. 3, an absorbent article 10" is shown which contains afirst absorbent layer 12, a second absorbent layer 13 and a baffle 14. Alongitudinally-extending garment adhesive strip 20 is attached to theexterior surface of the baffle 14 and is covered by a removable peelstrip 21. The garment adhesive 20 is commercially available. One companythat sells this adhesive is National Starch Co. located at 10 FinderneAve. Bridgewater, N.J. 08807. The garment adhesive 20 is used to securethe absorbent article 10" to the inside of the crotch portion of anundergarment (not shown), so that it can be properly aligned to coverthe vaginal opening. The peel strip 21 is releasably attached to thegarment adhesive strip 20 to prevent the adhesive from becomingcontaminated prior to attachment to the undergarment. The peel strip 21can be a white Kraft paper, coated on one side so that it can bereleased from a hot melt adhesive. The peel strip 21 is designed to beremoved by the ultimate consumer just prior to placement of theabsorbent article 10" in the undergarment. It should be noted that, inFIG. 3 , no cover is present. A cover is designed to be utilized in thepreferred embodiment.

Referring to FIG. 4, an absorbent article 110 is shown which is similarin construction to the absorbent article 10 shown in FIG. 1. Theabsorbent article 110 has an hourglass-shaped, central absorbent 117with two longitudinally extending side edges 118 and 119. Each of theside edges 118 and 119 has a concave central portion 120 and 121,respectively, shown by dotted lines. The absorbent article 110 furtherhas two garment attachment panels 130 and 131, which extend outward fromthe central absorbent 117, along each of the concave central portions120 and 121. The garment attachment panels 130 and 131 extend in atransverse direction outward from the central absorbent 117 and aredesigned to wrap around the outer surface of the crotch portion of anundergarment. The garment attachment panels 130 and 131 will extendlaterally outward and lie in the same plane as the widest portion of theabsorbent article 110. The garment attachment panels 130 and 131 can beconstructed from the same materials as the baffle and/or theliquid-permeable cover 111.

Preferably, the garment attachment panels 130 and 131 will be anextension of both the baffle and the liquid-permeable cover 111. In anoptional embodiment, at least one of the garment attachment panels 130and 131 may have an adhesive strip 139, attached to its upper surface,which is covered by a releasable peel strip 140. The absorbent article110 can also have at least one garment adhesive strip (not shown)secured to the central, exterior surface of the baffle, which can becovered by another releasable peel strip. When the consumer is ready towear the product, the central peel strip is removed, and the absorbentarticle 110 is adhered to the inner surface of the undergarment via thegarment adhesive. The consumer then removes the peel strip 140, attachedto one of the garment attachment panels, and wraps the garmentattachment panels 130 and 131 around the exterior surface of theundergarment. One garment attachment panel can then be adhered to theother garment attachment panel by the adhesive 139.

The garment attachment panels 130 and 131 preferably do not contain anyabsorbent material; although they could, if desired. The garmentattachment panels 130 and 131 could be constructed of baffle materialonly. In such a case, it is desirable, for the comfort of the wearer, ifa thin layer of absorbent material is placed on the body-facing side ofat least one, and preferably both, garment attachment panels 130 and131. In such a case, the baffle will preferably have an hourglass shape,with the garment attachment panels 130 and 131 extending from thenarrow, central portion of the baffle and extending as far as the widestsection of the absorbent article 110. When absorbent material isincluded in the garment attachment panels 130 and 131, it will notinfluence soiling, since the function of the walls formed by the garmentattachment panels 130 and 131 is menstrual fluid containment rather thanabsorbency.

The absorbent layers contained in the absorbent article 110, rather thanthe garment attachment panels 130 and 131, will serve to absorb the vastmajority of the menstrual fluid. Furthermore, with little or noabsorbent material present in the garment attachment panels 130 and 131,the absorbent article 110 will be less bulky and more comfortable to theuser.

Referring to FIG. 5, an absorbent article 210 is illustrated which has acover 211 and an hourglass-shaped first absorbent layer 212. The cover211 contains a plurality of apertures or perforations 230 which areformed approximate the narrow portion of the absorbent article 210. Theapertures 211 permit body fluid to rapidly pass down into the firstabsorbent layer 212.

Referring to FIG. 6, an absorbent article 410 is shown which includes afirst liquid-impermeable baffle 412, a second liquid-impermeable baffle414 and a liquid-permeable cover 416. The bottom surface of the firstbaffle 412 faces the user's undergarment, while the cover 416 faces thebody of the user. A first absorbent layer 418 is positioned below thecover 416, and a second absorbent layer 420 is positioned on top of thefirst baffle 412. Preferably, the second baffle 414 is generally of thesame shape as the first absorbent layer 418. The second absorbent layer420 should have a higher transverse wicking rate than the firstabsorbent layer 418, and fluid staining on the second absorbent layer420 will be visible through the cover 416. The first baffle 412 and thecover 416 can be coterminous and will define the exterior periphery ofthe absorbent article 410.

Construction adhesives, which adhere the various layers of the absorbentarticle to each other, and garment attachment adhesives, which adherethe absorbent article to the undergarment, may be any of those typicallyutilized in formation of sanitary napkins, diapers, training pants orincontinence garments. A preferred construction adhesive material is ahot-melt type adhesive, although other suitable adhesives may be used. Apreferred method of attaching the absorbent article to an undergarmentis by a single, wide band of adhesive which is selected for maximumattachment strength.

EXAMPLES

The following examples are being presented for the purpose ofillustration only. In these examples, a modified U.S. government test#DDD-P-66B was followed. In our examples, the absorbency of an absorbentarticle was determined by laying the product on a flat, level,transparent surface, so that the underside of the absorbent articlecould be observed. A mirror was placed under the suspended surface tofacilitate the observation of the underside of the absorbent article. Aone percent (1%) dye solution of distilled water was applied to thecenter of the product. The temperature of the dye solution was 73° F.,±3°. The dye solution was applied from a burette at the rate of 15milliliters/minute, ±3 ml, from a height of approximately one inch. Atotal insult of 5 ml of dye solution, for the Examples in Table 1, and10 ml of dye solution, for the Examples in Table 2, was applied. Thewidth and length of the stain in each Example was measured after 5 and10 minutes, respectively, total elapsed time.

Referring to Table 1, the size of a liquid stain for a 5 milliliter (ml)insult of solution after 5 and 10 minutes, respectively, for differenttypes of a single material is shown. The first entry is "Blotting Paper,unscored (75% Bleached Softwood, 25% Northern Pine)". The dimension ofthe first test sample was 60 millimeters (mm) wide by 182 mm long. Theliquid stain, after five minutes, was 47 mm wide by 89 mm long and,after 10 minutes, was 47 mm wide by 93 mm long. Table 1 is for referencepurposes only and is not illustrative of the present invention.

Referring to Table 2, which is illustrative of the present invention(except Example 12), stain dimensions for a 10 ml insult of solution onvarious materials is shown. Each material was placed under the fluffpulp core taken from a Kotex® Maxi Pad. The dimension of the fluff pulpcore taken out of the Kotex® Maxi Pad was approximately 60 mm. wide by150 mm. in length. The first entry (Example 10) was "Blotting Paperunscored (75% Bleached Softwood, 25% Northern Pine)." Two sets of dataare shown. The first set of data (the first two horizontal rows) is forthe second absorbent layer oriented in the "machine direction." By"machine direction," it is meant that the second absorbent layer wasaligned parallel to the longitudinal axis of the absorbent article."Cross direction" means that the second absorbent layer was alignedperpendicular to the longitudinal axis of the absorbent article. Asample 60 mm wide by 178 mm long was placed under the first absorbentlayer. After 5 minutes, the stain on the first absorbent layer was 44 mmwide by 55 mm long, while the stain on the second absorbent layer was 60mm wide by 123 mm long. After 10 minutes, the stain sizes were 46 mmwide by 59 mm long, and 60 mm wide by 133 mm long, respectively.Accordingly, this sample is an example of the present invention.

The second set of data for Example 10, listed in Table 2, (the third andfourth horizontal rows) is for the second absorbent layer oriented in across direction. This data demonstrates even more transverse wicking inthe second absorbent layer. After 5 minutes, the stain sizes were 125 mmwide by 60 mm long; and after 10 minutes, the stain sizes were 150 mmwide by 60 mm long. Example 10 (60 grams per square meter (gsm) ofmeltblown polypropylene with surfactant treatment) demonstrates thegreatest wicking properties and represents one preferred embodiment ofthis invention.

It should be noted that the cross direction orientation of the materialin the second absorbent layer enhances the lateral fluid-distributionproperties of that layer, see examples 10 and 11. It should also bementioned that, for Example 12, the second absorbent layer did not wickfluid as far as the first absorbent layer and, therefore, is not anexample of this invention.

                  TABLE 1                                                         ______________________________________                                        Ex-                 Dimension        Stain After                              am-                 of Mat'l.                                                                              Stain After                                                                           10 Min.                                  ple  Material       In mm    5 Min. (mm)                                                                           (mm)                                     ______________________________________                                        1    BLOTTING PAPER W = 60   W = 47  W = 47                                        UNSCORED       L = 182  L = 89  L = 93                                        (75% BLEACHED                                                                 SOFTWOOD, 25%                                                                 NORTHERN PINE)                                                           2    BLOTTING PAPER W = 63   W = 45  W = 47                                        SCORED         L = 125  L = 88  L = 91                                        (75% BLEACHED                                                                 SOFTWOOD, 25%                                                                 NORTHERN PINE)                                                           3    GELOK 8007     W = 63   W = 44  W = 45                                        A/A SAB-840    L = 169  L = 45  L = 45                                   4    BG 13 gsm      W = 150  W = 139 W = 142                                       2 PLY TISSUE   L = 180  L = 93  L = 99                                        (100% LONGLAC                                                                 SOFTWOOD)                                                                5    BG 13 gsm      W = 150  W = 111 W = 117                                       4 PLY TISSUE   L = 233  L = 67  L = 74                                        (100% LONGLAC                                                                 SOFTWOOD)                                                                6    KLEENEX ® TISSUE                                                                         W = 219  W = 151 W = 156                                       (30% SOFTWOOD  L = 228  L = 107 L = 108                                       70% HARDWOOD)                                                            7    HI DRI ®   W = 113  W = 100 W = 103                                       PAPER TOWEL    L = 282  L = 172 L = 178                                       (100% RE-PROCESSED                                                            PULP)                                                                    8    60 gsm MELTBLOWN                                                                             W = 154  W = 52  W = 53                                        (POLYPROPYLENE)                                                                              L = 152  L - 64  L = 66                                        INSERT FROM                                                                   NEW FREEDOM ®                                                             MAXI                                                                     9    KOTEX ® MAXI                                                                             W = 58   W = 35  W = 38                                        FLUFF INSERT   L = 152  L = 44  L = 48                                   ______________________________________                                    

                                      TABLE 2                                     __________________________________________________________________________                      Dimensions                                                                          Stain on                                                                              Stain on                                      Composition       of Second                                                                           First Abs.                                                                            Second Abs.                                   of Second         Abs. Layer                                                                          Layer In mm                                                                           Layer In mm                                   Example                                                                            Absorbent Layer                                                                            In mm 5 Min                                                                             10 Min                                                                            5 Min                                                                              10 Min                                   __________________________________________________________________________    10   BLOTTING PAPER                                                                             W = 60                                                                              W = 44                                                                            W = 46                                                                            W = 60                                                                             W = 60                                        UNSCORED     L = 178                                                                             L = 55                                                                            L = 59                                                                            L = 123                                                                            L = 133                                       (75% BLEACHED                                                                              W = 357                                                                             W = 28                                                                            W = 35                                                                            W = 125                                                                            W = 150                                       SOFTWOOD, 25%                                                                              L = 60                                                                              L = 36                                                                            L = 42                                                                            L = 60                                                                             L = 60                                        NORTHERN PINE)                                                           11   BLOTTING PAPER                                                                             W = 64                                                                              W = 34                                                                            W = 35                                                                            W = 51                                                                             W = 53                                        SCORED       L = 250                                                                             L = 55                                                                            L = 60                                                                            L = 11O                                                                            L = 118                                       (75% BLEACHED                                                                              W = 175                                                                             W = 31                                                                            W = 35                                                                            W = 145                                                                            W = 162                                       SOFTWOOD, 25%                                                                              L = 65                                                                              L = 38                                                                            L = 42                                                                            L = 60                                                                             L = 66                                        NORTHERN PINE)                                                           12   GELOK 8007   W = 64                                                                              W = 40                                                                            W = 44                                                                            W = 31                                                                             W = 34                                        A/A          L = 190                                                                             L = 55                                                                            L = 64                                                                            L = 33                                                                             L = 33                                        SAB-840                                                                  13   BG 13 gsm    W = 151                                                                             W = 44                                                                            W = 49                                                                            W = 97                                                                             W = 100                                       2 PLY        L = 166                                                                             L = 44                                                                            L = 45                                                                            L = 80                                                                             L = 87                                        TISSUE (100%                                                                  LONGLAC SOFTWOOD)                                                        14   BG 13 gsm    W = 151                                                                             W = 33                                                                            W = 39                                                                            W = 104                                                                            W = 113                                       4 PLY TISSUE L = 166                                                                             L = 42                                                                            L = 44                                                                            L = 83                                                                             L = 94                                        (100% LONGLAC                                                                 SOFTWOOD)                                                                15   KLEENEX ® TISSUE                                                                       W = 219                                                                             W = 42                                                                            W = 44                                                                            W = 131                                                                            W = 150                                       (30% SOFTWOOD                                                                              L = 228                                                                             L = 45                                                                            L = 46                                                                            L = 126                                                                            L = 143                                       70% HARDWOOD)                                                            16   HI DRI ® W = 113                                                                             W = 44                                                                            W = 48                                                                            W = 80                                                                             W = 88                                        PAPER TOWEL  L = 282                                                                             L = 42                                                                            L = 44                                                                            L = 109                                                                            L = 112                                       (100% RE-PROCESSED                                                            PULP)                                                                    17   60 gsm       W = 154                                                                             W = 37                                                                            W = 40                                                                            W = 165                                                                            W = 126                                       MELTBLOWN    L = 152                                                                             L = 41                                                                            L = 42                                                                            L = 136                                                                            L = 143                                       (POLYPROPYLENE)                                                               INSERT FROM                                                                   NEW FREEDOM ® MAXI                                                   __________________________________________________________________________

The ratios of the width of the stain, for the materials listed in Table2, were calculated over a predetermined time period. Accordingly, the"transverse wicking rate" is equal to the stain width per unit time. Theratios are listed in Table 3 below for time periods of 5 and 10 minutes,respectively. The ratio is obtained by dividing the value for the secondabsorbent layer by the value of the first absorbent layer. For example,for Example 10 in the cross direction at 5 minutes, 125/28=4.5 roundedto one place after the decimal point.

                  TABLE 3                                                         ______________________________________                                        Stain width in Stain width in                                                                            Ratio  Ratio                                       1st Layer (mm) 2nd Layer (mm)                                                                            5      10   Com-                                   Example                                                                              5 Min   10 Min  5 Min 10 Min                                                                              Min. Min. ments                            ______________________________________                                        10  MD     44      46    60    60    X    X    Note 1                             CD     28      35    125   150   4.5  4.3                                 11  MD     34      35    51    53    1.5  1.5                                     CD     31      53    145   162   4.7  3.1                                 12  MD     40      44    31    34    X    X    Note 2                         13  MD     44      49    97    100   2.2  2.8                                 14  MD     33      39    104   113   3.2  2.9                                 15  MD     42      44    131   150   3.1  3.4                                 16  MD     44      48    80    88    1.8  1.8                                 17  MD     37      40    165   126   4.5  3.2                                 ______________________________________                                         MD = machine direction                                                        CD = cross direction                                                          Note 1: X indicates that a ratio was not calculated because the stain         reached the longitudinal edges of the second absorbent layer.                 Note 2: X indicates that a ratio was not calculated because the stain was     smaller on the second layer than on first layer.                         

One will notice that the ratio of the transverse wicking rate of thesecond absorbent layer, when aligned in a machine direction, to thefirst absorbent layer is greater than about 1.5 after 5 minutes, andgreater than about 1.5 after 10 minutes. One will also notice that theratio of the transverse wicking rate of the second absorbent layer, whenaligned in a cross direction, to the first absorbent layer is greaterthan about 4.5 after 5 minutes and greater than about 3.1 after 10minutes.

While the invention has been described in conjunction with severalspecific embodiments, it is to be understood that many alternatives,modifications and variations will be apparent to those skilled in theart in light of the aforegoing description. Accordingly, this inventionis intended to embrace all such alternatives, modifications andvariations which fall within the spirit and scope of the appendedclaims.

We claim:
 1. A sanitary napkin having a central transverse axis and agenerally hourglass configuration with longitudinal edges each having aconcave central portion comprising:a) a liquid-permeable cover; b) aliquid-impermeable baffle; c) a first absorbent layer positioned betweensaid cover and said baffle; d) a second absorbent layer positionedbetween said first absorbent layer and said baffle; said first andsecond absorbent layers being enclosed by said cover and said baffle,said second absorbent layer having a higher transverse wicking rate thansaid first absorbent layer; e) a third absorbent layer positionedbetween said first and second absorbent layers, said third absorbentlayer having a width measured along said central transverse axis whichis greater than said first absorbent layer but less than said secondabsorbent layer and said third absorbent layer having a transversewicking rate which is less than a transverse wicking rate of said secondabsorbent layer; and f) a pair of garment attachment panels integrallyformed from said cover and said baffle, said garment attachment panelsextending laterally from said concave central portion of each of saidlongitudinal edges and laying in the same plane as the widest portion ofsaid sanitary napkin.
 2. An absorbent article for absorbing body fluidhaving a central transverse axis, said absorbent article comprising:a) afirst absorbent layer; b) a second absorbent layer having an ovalconfiguration with a higher transverse wicking rate than said firstabsorbent layer, said second absorbent layer having a width measuredalong said central transverse axis which is greater than that of saidfirst absorbent layer; and c) a third absorbent layer positioned betweensaid first and second absorbent layers, said third absorbent layerhaving a width measured along said central transverse axis which isgreater than said first absorbent layer but less than said secondabsorbent layer and a transverse wicking rate which is less than saidsecond absorbent layer, said greater width and higher transverse wickingrate of said second absorbent layer enabling body fluid to betransversely routed in said second absorbent layer faster than in eithersaid first or third absorbent layers whereby a user can visually inspectsaid absorbent article to determine if said absorbent article isapproaching its maximum fluid capacity.
 3. The absorbent article ofclaim 2 wherein said first absorbent layer contains a superabsorbent andsaid second absorbent layer has a thickness less than that of said firstabsorbent layer.
 4. The absorbent article of claim 2 wherein said secondabsorbent layer contains a superabsorbent.
 5. The absorbent article ofclaim 2 wherein the transverse wicking rate ratio of said secondabsorbent layer to said first absorbent layer is greater than about 1.5after 5 minutes.
 6. The absorbent article of claim 2 wherein thetransverse wicking rate ratio of said second absorbent layer, whenaligned in a cross direction, to said first absorbent layer is greaterthan about 3.1 after 10 minutes.
 7. The absorbent article of claim 2wherein the transverse wicking rate ratio of said second absorbentlayer, when aligned in a machine direction, to said first absorbentlayer is greater than about 1.5 after 10 minutes.
 8. An absorbentarticle for absorbing body fluid having a central transverse axis, saidabsorbent article comprising:a) a first absorbent layer; b) a secondabsorbent layer having a width measured along said central transverseaxis which is greater than that of said first absorbent layer, saidsecond absorbent layer having a higher transverse wicking rate than saidfirst absorbent layer; and c) a third absorbent layer positioned betweensaid first and second absorbent layers, said third absorbent layerhaving a width measured along said central transverse axis which isgreater than said first absorbent layer but less than said secondabsorbent layer and a transverse wicking rate which is less than saidsecond absorbent layer, said greater width and higher transverse wickingrate of said second absorbent layer enabling body fluid to betransversely routed in said second absorbent layer faster than in eithersaid first or third absorbent layers whereby a user can visually inspectsaid absorbent article to determine if said absorbent article isapproaching its maximum fluid capacity.
 9. The absorbent article ofclaim 8 wherein said third absorbent layer has a thickness greater thansaid first and second absorbent layers.
 10. The absorbent article ofclaim 8 wherein said first absorbent layer has an hourglassconfiguration, said second absorbent layer has an oval configuration andsaid third absorbent layer has a rectangular configuration.
 11. Theabsorbent article of claim 8 wherein said second and third absorbentlayers contain a superabsorbent.
 12. An absorbent article for absorbingbody fluid having a central transverse axis and a generally hourglassconfiguration with a pair of longitudinal edges each having a concavecentral portion, said absorbent article comprising:a) a first absorbentlayer; b) a second absorbent layer having an oval configuration with athickness less than that of said first absorbent layer and a widthmeasured along said central transverse axis which is greater than thatof said first absorbent layer, said second absorbent layer having ahigher transverse wicking rate than said first absorbent layer; c) athird absorbent layer positioned between said first and second absorbentlayers, said third absorbent layer having a width measured along saidcentral transverse axis which is greater than said first absorbent layerbut less than said second absorbent layer, said greater width and highertransverse wicking rate of said second absorbent layer enabling bodyfluid to be transversely routed in said second absorbent layer fasterthan in either said first or third absorbent layers whereby a user canvisually inspect said absorbent article to determine if said absorbentarticle is approaching its maximum fluid capacity; and d) a pair ofgarment attachment panels extending laterally outwardly from one of saidconcave central portions and lying in the same plane as the widestportion of said absorbent article.